Various conventional panel style air filter designs contain a pleated media pack. Areas of the media pack structure must be sealed with a compound such as hot melt adhesive. Additionally, the edges of the pleat packs are typically sealed with an adhesive such as hot melt adhesive. As the hot melt adhesive is applied to the media pack structure and the edges of the pleat packs, the adhesive may render a usable area of the filter media unusable by masking the filter media. Masked areas of the filter media reduce the overall efficiency and performance of the air filter. Further, hot melt adhesive is prone to becoming plugged and having air pockets in the dispensing system that cause sputtering when the hot melt adhesive is applied. These inconsistencies in the hot melt adhesive may cause an interruption or a break in the hot melt bead, which leads to a leak path through the filter. If a leak path exists in the filter, the filter's efficiency may be reduced.
In conventional panel style air filters, as the filter media loads with contaminant or as flow increases, unsupported media pack layers tend to collapse against each other. Masking off of usable filter media may occur where the packed layers are collapsed against each other, which may increase the resistance of flow through the filter media. The increased flow resistance may reduce the filter's efficiency and may reduce the filter life.
Still further, government regulations are driving changes in the available space for air filters in engine compartments. Conventional panel style air filters typically come in square, rectangular, or cylindrical shapes. Air cleaner designs with improved shape flexibility to fit available space envelopes within engine compartments may provide automobile designers with increased design options.